Many Graco Reactor proportioners offer multiple heating methods to keep materials at the proper application temperature. One of these options is resistance mode, which allows the machine to continue operating if the primary temperature sensing system is unavailable or requires troubleshooting. Understanding when and how to use resistance mode can help contractors minimize downtime while protecting their equipment.
Whether you operate a new or spray foam insulation machine or purchase a used rig, knowing how resistance mode works is an important part of maintaining consistent performance.
What Is Resistance Mode on a Graco Reactor?
Resistance mode is an alternate heating control method available on many Graco Reactor proportioners. Instead of controlling heat through temperature feedback, the system estimates hose and heater temperature by monitoring electrical resistance within the heated hose circuit.
This operating mode is generally intended for troubleshooting or temporary operation until the primary temperature sensing issue can be corrected.
While resistance mode can keep production moving, contractors should always follow Graco’s operating recommendations and verify proper material temperatures throughout the spraying process.
When Should You Use Resistance Mode?
A spray foam insulation machine should normally operate in standard temperature control mode whenever possible. However, resistance mode may be useful when:
- A temperature sensor has failed.
- A hose temperature circuit requires troubleshooting.
- Temporary operation is necessary to complete a project.
- Waiting on replacement parts would create unnecessary downtime.
Because resistance mode estimates temperature rather than directly measuring it, operators should monitor material quality closely during operation.
How to Operate a Spray Foam Insulation Machine in Resistance Mode
Every Graco Reactor model has its own operating procedures, so always consult the equipment manual before making any control changes.
General best practices include:
- Verify all electrical connections before startup.
- Inspect heated hoses for damage.
- Confirm material temperatures before spraying.
- Allow the system to fully warm up.
- Perform a test spray before beginning production.
- Monitor pressure balance throughout the job.
- Watch material quality and spray pattern continuously.
- Return the machine to normal operating mode once repairs are completed.
Proper preparation helps ensure the spray foam insulation machine continues operating safely and consistently while in resistance mode.
Buying a Used Spray Foam Insulation Machine Already Running in Resistance Mode
If you’re considering purchasing a used spray foam insulation machine, it’s important to determine why the equipment is operating in resistance mode.
In some cases, the previous owner may simply be waiting on a replacement temperature sensor or electrical component. In other situations, resistance mode could indicate an underlying issue that should be repaired before regular production.
Before purchasing a used rig, contractors should inspect:
- Heater operation
- Heated hose condition
- Temperature sensors
- Electrical wiring
- Hose continuity
- Overall maintenance history
- Service records, if available
A properly inspected used rig can provide years of dependable service, but understanding why resistance mode is being used helps avoid unexpected repair costs.
Advantages of Understanding Resistance Mode
Learning how resistance mode works provides several benefits:
- Reduced jobsite downtime
- Faster troubleshooting
- Better understanding of Reactor controls
- More informed purchasing decisions
- Improved equipment reliability
Knowing when resistance mode is appropriate can help contractors stay productive while planning permanent repairs.
Choosing the Right Spray Foam Equipment
Whether you’re purchasing new equipment or evaluating a used spray foam insulation machine, selecting a reliable supplier is just as important as selecting the equipment itself.
Spray Foam Systems offers:
- New Graco Reactor proportioners
- Complete spray foam rigs
- Professionally maintained used rigs
- Heated hoses
- Spray guns
- Replacement parts
- Technical support
- Equipment training
Whether you’re purchasing new Graco spray foam equipment or a used rig, Spray Foam Systems offers professional equipment, replacement parts, technical support, and experienced guidance to help you evaluate equipment condition, maintenance history, and available inventory so you can purchase with confidence and keep your equipment operating efficiently.
FAQs
Can every spray foam insulation machine operate in resistance mode?
No. Resistance mode is available on many Graco Reactor models, but availability depends on the specific machine and control system. Always refer to your equipment manual.
Should I buy a used spray foam insulation machine that is operating in resistance mode?
It can still be a good investment, but you should determine why the machine is operating in resistance mode and inspect the heating system, sensors, hoses, and electrical components before purchasing.
Is resistance mode intended for everyday operation?
Generally, no. Resistance mode is typically used as a temporary operating method while troubleshooting or repairing the primary temperature sensing system.
About Spray Foam Systems
Spray Foam Systems is the #1 spray foam rig builder and spray foam equipment supplier in the United States. Family-owned and proudly serving the industry since 2007, we operate from a 7-acre campus with over 80,000 square feet of dedicated working space in Greensboro, GA. With over 10,000 customers served over the last 18 years, we specialize in delivering high-quality turnkey spray foam systems, distributing top-tier equipment and supplies, and providing nationwide service and training to help contractors grow and succeed in the spray foam insulation and roofing markets.